(as) soft as a baby's bottom
Exceptionally soft and/or smooth. I love how your face feels after you shave—it's as soft as a baby's bottom! This is my favorite blanket to get snuggled up in at night. It's soft as a baby's bottom, and it keeps me nice and warm in bed.
*soft as a baby's bottom
and soft as a baby's backside; *soft as down; *soft as silk; *soft as velvetCliché very soft and smooth to the touch. (*Also: as ~.) This cloth is as soft as a baby's bottom. The kitten's fur was as soft as down. Your touch is soft as silk. This lotion will make your skin soft as velvet.